This is a transcript of a radio address broadcast for the Center for Public Justice on KDCR radio in Sioux Center, Iowa.

A few weeks ago, I talked about a social crisis, based on growing divisions of class, that threatens the American ideal. A number of problems among working class families—less parental time with children, less community and religious involvement, less academic achievement and social trust—are predicting a social mobility crash for millions of Americans.

There are a number of causes. One is clearly the collapse of working class families. Another is the disappearance of well paid, lower skilled jobs in many communities over the last few decades. Another is the decay of working class neighborhoods, which used to have stronger networks of models and mentors outside the home.

Whatever the mix of causes, the result is a durable, deepening national divide, increasingly rooted in class.

This is an attack on the self-image of America. Americans are generally comfortable with the existence of inequality in a free economy, as long as economic advancement is a realistic goal. But economic inequality without economic mobility is just a caste system, in which birth is destiny.

Yet if you listen to the current political debate, you won’t hear much on this topic. Republicans tends to talk about economic freedom. Democrats tend to talk about making the tax code more progressive. And both parties tend to talk most about the middle class, rather than the poor or working class, because that is where political advisors tell them the votes are.

But eventually political leaders will be required to deal with the opportunity gap. The challenge is to have the ideas and policies ready. A number of groups are doing that groundwork, including the Economic Mobility Project, Opportunity Nation and the Center for Public Justice.

We know that economic mobility is strongly correlated with the structure of families. Children raised in single parent families are more likely to experience poverty and drop out of school and less likely to keep a job.

We know that economic mobility is strongly correlated with education. A college degree is the major factor in determining who will move up the economic ladder. Yet only 30 out of 100 high school students will graduate from college.

We know that economic mobility is connected to the health of communities. It is lower in socially disorganized and economically depressed neighborhoods.

We know that economic mobility is influenced by physical health while also leading to better health outcomes. Low birth weight and other physical conditions in early childhood can limit academic achievement and earnings in adulthood.

We know that economic mobility is often enabled by wealth, savings and entrepreneurship. Entrepreneurs who last five years in business have more upward mobility than wage workers.

Policy approaches in these broad categories will vary. Some will require government. Others, churches and charities. Others, volunteers. But all of these efforts require the recognition that equality of opportunity is not a natural state, but a social achievement, for which all of us are responsible, in one way or another.

—Michael J. Gerson is nationally syndicated columnist who appears twice weekly in The Washington Post and is the author of Heroic Conservatism (2007) and the co-author of City of Man: Religion and Politics in a New Era (2010).